John’s Revelation Unveiled – Part 2

Furthermore, the spectre seen by John was that of "a great red Dragon" with "ten horns."471 This corresponds to the Roman or fourth "great" Beast in Daniel's vision. For that Beast there was "dreadful and terrible and exceedingly strong"  with "great iron teeth" and "ten horns."495

Moreover, John's Dragon had "seven crowns" upon its seven heads. These seven crowns and heads were probably successive and not contemporaneous. But either way, they clearly identify the beast as the temporal political power corresponding to the "seven mountains" surrounding the ancient city of Rome.